The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingBack door
The back door can be locked/unlocked and opened/closed by
the following procedures.
Locking and unlocking the back door
Door lock switch
Entry function (if equipped)
Wireless remote control
Opening/closing the back door from inside the vehicle (vehicles
with a power back door)
Press a ...
Shift solenoid "d" performance (shift solenoid valve s4)
System description
The ecm uses signals from the output shaft speed sensor and input speed
sensor to detect the actual
gear position (1st, 2nd, 3rd or o/d gear).
Then the ecm compares the actual gear with the shift schedule in the ecm memory
to detect mechanical
problems of the shift s ...
Sliding roof control switch circuit
Description
If either the sliding function or tilt function does not operate, there may
be a malfunction in the sliding roof
control switch circuit.
Wiring diagram
Inspection procedure
Perform active test by intelligent tester (sliding roof operation)
Select the active test, use ...